Builder&#39;s hardware



Patented Feb. 3 E833 aaeaa nnvm n. Jamison, or wanna, rnmnois BUILDEESHAIR-DWE ipplication filed. March 14, 1980. Serial No. 435,719.

My invention relates to builders hardware and includes among its objectsand advantages the provision of an improved secret door latch havingpositive action independ-.

cut of the speed of movement.

In the accompanying drawing, Fig. 1 is a side elevation of a lock,according to the invention, with the cover of the housingremoved.

Fig. 2 is a section on line 2-2 of Fig. 1.

Fig. 3 is a view similar to Fig. l with the parts in position forwithdrawal, and

Fig. 4 is a section on line 4 4 of Fig. 1.

Housing and ejector In the embodiment of the invention selected forillustration, is a movable element such as a door or lid, and 12 is afixed element such as a door jamb or the side of a box or cabinet. Theretaining hook .14 is mounted on movable element 10, and the housing 16and parts carried thereby are mounted on the fixed element 12. In thelower portion of the housing I provide a cast partition 18 spaced fromthe bottom'wall 20 of the housing to define a channel receiving theejector 22. The ejector comprises a cylindrical body slidable throughthe hole 24 in the front of the casing and a head 26 to limit theoutward movement. The coil spring 28 tends to move the ejector againstthe movable element 10. The spring 28 may be adjustably tensioned by theabutment nut 30 to give the correct action under a wide variety ofloadings.

Retaining means The latch 32 is pivoted on the pintle 34 and terminatesin a retaining toe 36. The outer face of the toe 36 and the inner faceof the hook 14 are sloped so that movement of the hook inwardly to theposition of Fig. 1 will push the latch up above the position of Fig. 1until the hook has passed under the toe 36, when the latch will movedown to the position of Fig. 1, and the parts are firmly held againstseparation. To secure the prompt return of the latch I provide suitablebiasing means such as a wire spring 38 housed in a kerf in the latchmember and wound around the pintle 34. The stop pin 40 limits thedownward movement of the latch when the parts are'not' engaged.

Release The latch 32 has a cylindrical recess 42 with its lower sideopen. The release dog comprises a pintle member 44 and a dog proper 46.The connection between the pintle member 44.and the dog 46 is of suchwidth that the parts may rotate almost thirty degrees, being limited bythe engagement between the dog and the toe 36 in one direction, and inthe other direction by engagement of the shoulder 47 with the body ofthe latch 32. The faces of the dog 46 are at such angles that it willride over the hook 14 during movement in either direction. They divergemuch less by reason of the lost motion permitted by rotation around thepintle 44. This tipping always increases the slope of the surface withwhich the hook happens to be engaged at the time.

To release the door 10 it need only be pushed further into the positionof Fig. 3. During this inward movement the advancing face of the hook 14will engage the front face of the dog and push the latch up until thedog rides over the hook 114 and the parts move down again to theposition of Fig. 3. There is now 30 no impediment to withdrawal of thehook, and the ejector 22 will open the door. The inner face of the dog46 will ride over the hook 14 and again lift the latch. ,The tip of thedog 46 projects just a trifle below the lower end of the toe 36 so thatthe tip of the hook 14 will be safely guided under the too 36 during itsoutward movement.

Reversibility screws 50 have their center lines just a little clear ofthe casing cover 52. This sets the wood screws well in from the edge ofthe door. By making the hook 14 symmetrical about a. horizontal medianplane, the hook casting can be rotated 180 about a horizontal axis fromthe osition of Fi 1 and assembled on either le hand or' rig t handdoors, with equal facility and with the offset in the right direction.

In either position, the base plate 48 extends far enough to function asan abutment or strike plate for the end of the ejector 22. In eitherposition the, lower prong of the hook 14 moves just above the wall 18.If the hinges permit the door to sag, this lower prong will slide on thewall 18 and prevent the door from sagging enough to interfere withproper operation'of the lock.

The cover plate 52 completes'the housing for the ejector 22 and spring28, and is apertured to receive wood screws which may also pass throughthe apertures 54 in the bottom of the casing to fasten the cover plateand housin in place on the cabinet wall 12. A pair 0 bosses 56 areformed in the housing casting to enter registering holes in the coverate. a

P Without further elaboration, the foregoing will 'so fully explain myinvention that others may, b applying-knowledge current at the time 0application, readily adapt the same for use under various conditions ofservice.

I claim:

1. The combination with a fixed member and a movable member, of a housincarried by said fixed member, a hook carrie by said movable member, a sring pressed latch member, said latch mem r and hook having inwardlyfacing hook surfaces for holding the hook against withdrawal, and meansmounted upon said latch member and actuated by movement of said hookinwardly beyond latched position for lifting said latch member to clearsaid hook and release it upon subsequent outward movement of said hook,said hook being symmetrical about a median plane and having a portionpositioned substantially in contact with one surface of the housing.

2. An automatic latch holder including a hook, a housing, a springpressed latch member carried by said housing, said latch member and hookhaving outwardly facing cam surfaces to deflect said latch member andpermit entry of said hook, said latch member and hook having flatsurfaces defining hook portions for permitting said latch member toreturn and for holding said hook against withdrawal thereafter, a camdog tiltably mounted on said latch member behind the hook surfacethereof and shaped to deflect the latchmember and ride over the hook ineither. direction, said cam dog having a flat face facing the fiatsurfaces upon said latch member, said hook being wedged between the flatfaces. upon the cam dogA and the latch when sald latch member and e hookare in latched relation said dog when'tilted in the direct1on of theflat surface u on the latch member, having its flat surface yin againstthe flat surface upon the latch mem r and extending coming wed edbetween said first-mentioned hook and t e movable element associatedtherewith, said wedged connection resisting normal forces on the door,but yieldable upon the a plication of an abnormal force to permit t esecond hook to be moved to a position upon the opposite side of the saidmovable element, whereby the latter will prevent said second hook frombecoming wedged between the movable element and said first mentionedhook when withdrawn therefrom.

In testimony whereof I hereunto aflix my signature.

ELVIN H. JOHNSON.

